Two stopovers. 19 hours's stay over. Do I need a visa?

I'm flying from San Francisco, USA to Kathmandu, Nepal via China Eastern Airlines. I have two transits. My plane will land in Shanghai where I will have to wait for 5 hours to board a plane to Kunming. The stay-over time in Kunming is 14 hours. Then, I will board a plane to Kathmandu. I will be there for 19 hours in total. Somebody told me the plane from Shanghai to Kunming is domestic and I will need a transit G. Is that true? If there is a delay of a few hours and it exceeds 24 hours, do I still need one? If yes, will I be able to get it at the airport?